Glutamate transporter 1 (GLT-1) is the major glutamate transporter in the brain, and is predominantly expressed in astrocytes, but at lower levels also in excitatory terminals. GLT-1 is best understood for its critical role in preventing neuronal excitotoxicity and brain seizures in the central nervous system (CNS). Maintaining the correct level of extracellular glutamate is crucial for neuronal transmission and network activity.